Today I am going to ask a provocative question. Are we cooling the planet with Sulfur Dioxide (SO2)?

Cooling you might say? I thought we were warming? It could be that we are keeping the planet 4C cooler than it would have been (and still appear to be warming).

Sulfur dioxide “is the chemical compound with the formula SO2. It is a toxic gas with a pungent, irritating smell, that is released by volcanoes and in various industrial processes. ”

USGS: “The most significant climate impacts from volcanic injections into the stratosphere come from the conversion of sulfur dioxide to sulfuric acid, which condenses rapidly in the stratosphere to form fine sulfate aerosols. The aerosols increase the reflection of radiation from the Sun back into space, cooling the Earth’s lower atmosphere or troposphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth’s surface of up to half a degree (Fahrenheit scale) for periods of one to three years. The climactic eruption of Mount Pinatubo on June 15, 1991, was one of the largest eruptions of the twentieth century and injected a 20-million ton (metric scale) sulfur dioxide cloud into the stratosphere at an altitude of more than 20 miles. ”

From 1850 to 1980 SO2 emissions rose from almost 0 to 140,000 Gigagrams per year in 1980 and then dropped down to 110,000 Gigagrams around 2000 and then it started to rise again as China began to burn a lot more coal.